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Vitamin D Toxicity: How much Vitamin D is too much?

Vitamin D is a necessary vitamin that acts as a hormone in the body. This powerful nutrient directly affects many aspects of your health and organs. (1)

Since it is a fat-soluble vitamin, it is possible to get too much vitamin D through supplement form. It is impossible to get too much through food alone, however.

There are two forms of vitamin D called D2 and D3. We get vitamin D2 from many foods, and we need to attain vitamin D3 through sunlight or supplementation or both.

Both of these forms must pass through the liver and the kidneys to convert to the final form of vitamin D, which is essential for heart, bone, and immune system health.

Vitamin D is a complex vitamin because it acts as a hormone, which is messenger molecules throughout the whole body. So, certain age groups require different dosages of vitamin D due to hormonal changes, such as menopause for women.

It is also complicated because it is the only one of 13 vitamins that can be made by the human body. Many people around the world are deficient in vitamin D because vitamin D3 requires sunlight on the skin so the body can produce it. Nearly 50 percent of the population suffers from vitamin D deficiency. That is around one billion people globally. (2)

Since many are deficient in vitamin D, it is rare to get too much of this vitamin. However, many doctors do prescribe high dosages that are not available in stores, which can lead to overdose.

Vitamin D, also known as “the sunshine vitamin,” can play a role in preventing illness, bone spurts, digestive health, and more. There is more research that suggests humans may need more vitamin D than the typical standard recommendation. (3)

Those with higher levels of vitamin D tend to have lower mortality risks, lower chance of allergies like asthma and eczema, and even a lower chance of developing many types of cancer like colorectal cancer.

How much Vitamin D is too much? Vitamin D Toxicity

Do you think you are getting too much vitamin D in your diet through food or supplementation? Learn more about how much vitamin D is too much, symptoms of toxicity, the side effects, and exactly how much you should be taking below.

 

Vitamin D toxicity, also known as hypervitaminosis D, is rare but can be a severe condition. Eating vitamin D-rich foods alone will not cause vitamin D toxicity, but taking too many or too high of dosage through supplements can.

Vitamin D toxicity happens when there is a build-up of this fat-soluble vitamin in the body. That can happen because vitamin D is not water-soluble. That means, unlike water-soluble vitamins like vitamin C, it cannot pass through the body and excrete through urine.

With vitamin C, it passes quickly through the body, unless there is a slight over the maximum amount, as an example. Normal levels of vitamin C usually go through the body within two to four hours. (4)

Although you must indeed replenish vitamin C with food or supplements, it is a different case for vitamin D. Vitamin D is a fat-soluble vitamin, which means it can build up to high levels in the body. (5)

However, vitamin A and K do not need sunlight to convert to their final form in the body. Vitamin D must have adequate sunlight for the body to synthesize it to its final form.

The exact levels of too much vitamin D vary per person, based on absorption, other nutrient levels, age, and more. Too much vitamin D for anyone would exceed 50,000 IU on a regular and long-term basis. A typical piece of advice from many healthcare professionals is to supplement with about 1 to 2,000 IU to be on the safe side unless there is an extreme deficiency.

You can also get vitamin D in the form of D2 from some foods. Both types of vitamin D are necessary for optimal functioning in the body. They can help to prevent many illnesses like cancer, diabetes, heart disease, and more.

Be sure to eat a diet with plenty of nutrient-dense foods high in vitamin D like eggs, beef liver, dairy or fortified dairy-free alternatives, spinach, mushrooms, cod liver oil, tuna, chicken, and more. (6)

If you get too much vitamin D from supplements, symptoms are likely to set in. Common symptoms of too much vitamin D include weakness, digestive issues, and more. Read below to find out more about taking too much vitamin D.

Symptoms of too much Vitamin D (Overdose or Toxicity)

It is possible to get too much vitamin D because it is a fat-soluble vitamin. It is highly unlikely and rare to get too much vitamin D from your dietary intake alone.

Your body can get too much when you take extremely high doses of the supplement in vitamin D2 or D3 form. That typically needs to be medically prescribed.

Make sure to get plenty of vitamin D from food and keep vitamin D3 supplement levels to a minimum unless otherwise specified by a healthcare professional or doctor.

Signs that you are taking or getting too much vitamin D include:

  • Weakness
  • Frequent urination
  • Bone pains
  • Nausea
  • Vomiting
  • Poor appetite
  • Digestive issues such as constipation, stomach pain, diarrhea

Many people throughout the world are already deficient in vitamin D. Therefore, even though it is a fat-soluble vitamin, remember that it is rare to take too much.

You will likely only exceed the upper limit if you are take medically prescribed or higher dosages frequently, which can sometimes start at 50,000 International Units (IU) and go to 60,000 IU.

There are many side effects, symptoms, and warning signs of too much vitamin D. If your doctor recommends you start taking high doses of vitamin C at 60,000 IU regularly, seek out a second opinion because that can be dangerous.

Vitamin D can do more harm than good in frequent megadose.

Learn more about the side effects you can experience, along with the latest information on the proper dosages per age group and sexual orientation.

Side Effects of too much Vitamin D

Along with the symptoms listed above, too much vitamin D can negatively affect other aspects of your health and organs on an even deeper level. Remember to keep in mind that an overdose of vitamin D is rare.

When you take too much vitamin D, there is a build-up of calcium in the blood. (6) That can result in many potential risk factors, such as kidney stones listed below.

  • Raised blood levels
  • Hypercalcemia (too much calcium in the blood)
  • Kidney problems such as calcium stones
  • Kidney failure
  • Bone loss

The side effects of vitamin D are rare, just as it is to take too much. If you are taking low doses of vitamin D each day, you will likely be ok.

Keep in mind, all of that depends on how well you can digest and absorb vitamins and minerals past the cell membrane. It also depends on other nutrient levels. Vitamin D needs adequate amounts of magnesium, vitamin K, and calcium to absorb in the body.

Do you know if you are getting the proper amount of vitamin D in your diet and supplementation? Check out the information below for the correct dosages for each sex and age.

How much vitamin D should I take?

Vitamin D dosages vary between ages, males, and females. The typical standard dosage of vitamin D for babies ages 0 to 12 months is 400 IU. From 1 to 70 years of age, the recommended intake for both men and women is 600 IU, and over 70 years old is 800 IU.

These are standard amounts based on evergreen shifting data. They can vary with your level of absorption, other nutrients, and hormonal changes since vitamin D is a hormone.

Many people who do not get adequate sun exposure can benefit from a supplement of 1,000 to 2,000 IU. Be cautious of extremely high doses prescribed at over 60,000 IU, as that can cause adverse side effects and toxicity.

Try to start dosages at a lower level if you can and your way up to higher levels over time unless you are severely deficient. Your doctor or healthcare professional may recommend high doses for a short period if your levels are too low.

Conclusion

Vitamin D is an essential fat-soluble vitamin that acts as a hormone in the body. Everyone needs to consume vitamin D from both food, sun, and sometimes supplements. There are many foods you can add to your diet to get more vitamin D.

Side effects and symptoms of vitamin D overdose are rare, although it is a fat-soluble vitamin. That is because vitamin D requires sunshine or supplementation to convert to its final form in the body.

Just as vitamin D toxicity can cause adverse side effects, too little vitamin D can also. Many people throughout the world are deficient in vitamin D, so be sure to get your levels tested every year if you can.

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Evidence Based

This article is based on scientific evidence, and written, fact-checked & medically reviewed by health experts.

Throughout this article, you’ll find scientific references (highly trusted peer-reviewed scientific papers, links denoted by the numbers in the parentheses (1, 2, 3)).